Development of a lysis blood culture system in which the lysing system remains with the culture has been initiated. About 50 candidate primary lysing agents have been tested, of the Triton, Tween and other series. The system has all of the advantages of lysis-filtration and lysis-centrifugation. Cost is no more than for the conventional blood culture, and no special handling is required. Tween 20 has been selected as marginally better than the three or four other final surfactant candidates. The process is now patent pending, and commercial interest is high. Hopefully the system will be marketed.